Context` menu item is invoked from 'git gui blame'. If this
variable is set to zero, the whole history is shown.
+ Specifies the shell command line to execute when the corresponding item
+ of the linkgit:git-gui `Tools` menu is invoked. This option is
+ mandatory for every tool. The command is executed from the root of
+ the working directory, and in the environment it receives the name of
+ the tool as 'GIT_GUITOOL', the name of the currently selected file as
+ 'FILENAME', and the name of the current branch as 'CUR_BRANCH' (if
+ the head is detached, 'CUR_BRANCH' is empty).
+ Run the tool only if a diff is selected in the GUI. It guarantees
+ that 'FILENAME' is not empty.
+ Run the command silently, without creating a window to display its
+ Don't rescan the working directory for changes after the tool
+ Show a confirmation dialog before actually running the tool.
+ Request a string argument from the user, and pass it to the tool
+ through the 'ARGS' environment variable. Since requesting an
+ argument implies confirmation, the 'confirm' option has no effect
+ if this is enabled. If the option is set to 'true', 'yes', or '1',
+ the dialog uses a built-in generic prompt; otherwise the exact
+ value of the variable is used.
+ Request a single valid revision from the user, and set the
+ 'REVISION' environment variable. In other aspects this option
+ is similar to 'argprompt', and can be used together with it.
+ Show only unmerged branches in the 'revprompt' subdialog.
+ This is useful for tools similar to merge or rebase, but not
+ for things like checkout or reset.
+ Specifies the title to use for the prompt dialog. The default
+ Specifies the general prompt string to display at the top of
+ the dialog, before subsections for 'argprompt' and 'revprompt'.
+ The default value includes the actual command.
Specify the browser that will be used to display help in the
'web' format. See linkgit:git-help.